Bladeless obturator for use in a surgical trocar assembly

ABSTRACT

An obturator assembly for use in dissection of tissue includes an obturator housing, an obturator member mounted to the obturator housing and an obturator sleeve coaxially mounted about the obturator member and adapted for reciprocal longitudinal movement between a retracted position and an extended position. The obturator member includes an obturator rod and a penetrating end. The penetrating end defines a substantially planar dissecting segment and a central rod segment extending from the planar dissecting element. The planar segment of the penetrating end of the obturator member defines atraumatic outer edges which may be arcuate in character. The central rod segment defines a distal entry surface which is also atraumatic, and may be arcuate as well. In one embodiment, the distal entry surface of the central rod segment and the atraumatic edges of the planar dissecting segment are at least partially exposed from the nose shield when in the extended position of the obturator sleeve. The obturator sleeve may include a generally tapered nose shield for at least partially accommodating the penetrating end.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims the benefit of and priority to U.S.Provisional Application Ser. No. 60/998,016 filed on Oct. 5, 2007, theentire contents of which are incorporated herein by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to an obturator assembly for use inminimally invasive surgical procedures, such as endoscopic orlaparoscopic type procedures.

2. Background of the Related Art

Minimally invasive procedures are continually increasing in number andvariation. Forming a relatively small diameter temporary pathway to thesurgical site is a key feature of most minimally invasive surgicalprocedures. The most common method of providing such a pathway is byinserting a trocar assembly through the skin. In many procedures, thetrocar assembly is inserted into an insufflated body cavity of apatient. In such procedures, the trocar assemblies with seal mechanismsare utilized to provide the necessary pathway to the surgical site whileminimizing leakage of insufflation gases.

Trocar assemblies typically include an obturator which is removablyinserted through a cannula. The obturator may include a safety shieldwhich protects against unintentional puncturing by the sharpened tip ofthe obturator. The safety shield includes a mechanism which controls therelative movement and locking of the safety shield. One example of asafety shield mechanism is disclosed in commonly assigned U.S. Pat. No.6,319,266 to Stellon et al., the entire contents of which are herebyincorporated by reference.

SUMMARY

Accordingly, the present disclosure is directed to an obturator assemblyfor use in dissection of tissue. The obturator includes an obturatorhousing, an obturator member mounted to the obturator housing and anobturator sleeve coaxially mounted about the obturator member andadapted for reciprocal longitudinal movement between a retractedposition and an extended position. The obturator member includes anobturator rod and a penetrating end. The penetrating end defines asubstantially planar dissecting segment and a central rod segmentextending from the planar dissecting element. The planar segment of thepenetrating end of the obturator member defines atraumatic outer edgeswhich may be arcuate in character. The central rod segment defines adistal entry surface which is also atraumatic, and may be arcuate aswell. In one embodiment, the distal entry surface of the central rodsegment and the atraumatic edges of the planar dissecting segment are atleast partially exposed from the nose shield when in the extendedposition of the obturator sleeve. The obturator sleeve may include agenerally tapered nose shield for at least partially accommodating thepenetrating end.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present disclosure are describedhereinbelow with references to the drawings, wherein:

FIG. 1 is a perspective view of a trocar assembly in accordance with thepresent disclosure;

FIG. 2 is a perspective view with parts separated of the trocar assemblyillustrating the cannula assembly and the obturator assembly;

FIG. 3 is a perspective view of the obturator assembly of the trocarassembly;

FIG. 4 is a perspective view with parts separated of the obturatorassembly illustrating the obturator shield and the obturator member;

FIG. 5 is a side cross-sectional view of the obturator assembly takenalong the lines 5-5 of FIG. 3;

FIG. 6 is a second side cross-sectional view of the obturator assembly;

FIG. 7 is an enlarged view of the indicated area of detail of FIG. 6;

FIG. 8 is an enlarged view of the indicated area of detail of FIG. 6;

FIG. 9 is a perspective view of the leading end of the obturatorassembly;

FIG. 10 is a second perspective view of the leading end of the obturatorassembly;

FIG. 11 is a perspective view of the obturator member illustrating theobturator rod and the obturator penetrating head;

FIG. 12 is a side plan view of the obturator member;

FIG. 13 is an enlarged perspective view of the obturator penetratinghead;

FIG. 14 is a cross-sectional view of the obturator rod taken along theline 14-14 of FIG. 12;

FIG. 15 is a cross-sectional view taken along the lines 15-15 of FIG. 9;

FIG. 16 is a cross-sectional view taken along the lines 16-16 of FIG. 9;

FIG. 17 is a cross-sectional view taken along the lines 17-17 of FIG. 9;

FIG. 18 is a perspective view illustrating insertion of the trocarassembly within tissue;

FIG. 19 is a view similar to the view of FIG. 18 illustrating theobturator sleeve in a retracted position fully exposing the penetratinghead of the obturator member; and

FIG. 20 is a side cross-sectional view of the obturator housing andcannula housing illustrating the transverse shelf of the obturatorsleeve engaging the stop within the obturator housing.

DETAIL DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now in detail to the drawing figures, in which, likereferences numerals identify similar or identical elements, there isillustrated, in FIGS. 1 and 2, a trocar assembly constructed inaccordance with a preferred embodiment of the present disclosure, anddesignated generally by reference numeral 10. Trocar assembly 10 isparticularly adapted for use in minimally invasive surgical proceduressuch as endoscopic or laparoscopic procedures. Generally, trocarassembly 10 includes two principal subassemblies, namely, obturatorassembly 100 and cannula assembly 1000.

Cannula assembly 1000 may be any cannula assembly suitable for use in alaparoscopic surgical procedure. In one embodiment, cannula assembly1000 includes cannula housing 1002 and cannula sleeve 1004 extendingfrom the cannula housing 1002. Either or both cannula housing 1002 andcannula sleeve 1004 may be transparent in part or in whole and may befabricated from biocompatible metal or polymeric material. Cannulaassembly 1000 may include an internal seal such as a duck-bill valve orother zero closure valve adapted to close in the absence of a surgicalinstrument to prevent passage of insufflation gases through the cannulaassembly 1000.

With reference now to FIGS. 3-6, in conjunction with FIG. 2, obturatorassembly 100 includes obturator housing 102, obturator sleeve 104extending distally from the housing 102 and obturator member 106 atleast partially disposed within the obturator sleeve 104. Obturatorsleeve 104 defines obturator axis “x” and will be discussed in greaterdetail hereinbelow. Obturator housing 102 includes housing base 108 andhousing cap 110. Once the appropriate components are positionedtherewithin, housing base 108 may be connected to housing cap 110through engaging mating surfaces. For example, housing base 108 mayinclude resilient latches 112 extending from inner annular wall 114 ofhousing base 108 (FIG. 6). Latches 112 interlock with correspondinglydimensioned latch openings 116 within housing cap 110. To uniformlyconnect housing base 108 and housing cap 110 at least threecorresponding latches 112 and openings 116 are spaced evenly aroundinner wall 114 of housing base 108 and the periphery of housing cap 110.Housing base 108 further defines outer wall 118 depending distallyrelative to inner wall 114. Outer wall 118 receives cannula housing 1002as will be discussed.

Referring now to FIGS. 4-8, obturator sleeve 104 includes shield member120, shield collar 122 and shield nose 124. Each of these components isoperatively connected to each other to define an outer member ofobturator assembly 100. In one preferred embodiment, shield member 120is at least partially positioned within shield collar 122. Shield collar122 has a plurality of radially inwardly directed tabs 126 which arereceived within corresponding openings 128 of shield member 120 in asnap-fit relation (FIG. 7). Similarly, shield nose 124 may be at leastpartially positioned within shield member 120. Shield nose 124incorporates a plurality (e.g., two) of resilient locking tabs 130depending radially outwardly adjacent a proximal end of the obturatornose 124. Locking tabs 130 are received within corresponding openings132 adjacent the distal end of shield member 120 also in snap relationto connect the components (FIG. 8) thus providing for selectivedisengagement of the shield nose 124 from the shield member 120, e.g.,for the purposes of changing the obturator rod 158 (explained furtherbelow). Other means for connecting the components of obturator sleeve104 are also envisioned including bayonet couplings, adhesives, welding,tongue and groove arrangements, etc. In other embodiments, obturatorsleeve 104 is a single component. In the assembled condition, shieldcollar 122 of obturator sleeve 104 is disposed within housing base 108,and at least partially received within annular wall 134 of the housingbase 108. Obturator sleeve 104 is adapted for axial movement along axis“x” and relative to obturator housing 102.

Obturator sleeve 104 is spring biased in the distal direction by coilspring 136. In particular, coil spring 136 is received within internalbore 138 of shield collar 122 and engages internal shelf 140 of theshield collar 122. The proximal end of coil spring 136 is coaxiallymounted about spring mount 142 (see FIG. 6) depending from the interiorsurface of housing cap 110.

Shield collar 122 includes transverse shelf 144 extending outwardlyrelative to the obturator axis “x”. Shelf 144 limits the length ordistance of retracting motion of obturator sleeve 104 through itsengagement with collar stop 146 within housing cap 110. Specifically,shelf 144 travels within opening 146 a of collar stop 146 duringretracting longitudinal movement of obturator sleeve 104 and is limitedby its engagement with cross-beam 146 b of the collar stop 146 (see alsoFIG. 4).

With reference to FIGS. 9 and 10, shield nose 124 may be tapered,conical or frusto-conical in configuration, and is adapted to passthrough tissue and may be capable of dissecting through tissue. In onepreferred embodiment, shield nose 124 has an irregular shaped withrounded tip 148 and central aperture 150 extending through the roundedtip 148. In particular, shield nose 124 is generally tapered inconfiguration defining a complex curved arrangement. In a first profileof shield nose 124, the shield nose 124 includes opposed concavesurfaces 152. In a second profile (viewed at a 90° offset), shield nose124 defines convex or outwardly bowed surfaces 154. This alternatingconcave and convex arrangement provides a substantially reduced profile(in cross-section) compared to conventional conically shaped obturatorsthereby providing an enhanced ability to penetrate or pass throughtissue layers. Various radii of curvature are contemplated. Rounded tip148, by its arcuate configuration, minimizes the potential of undesiredor unintended piercing of tissue. Shield nose 124 also defines slot 156traversing the shield nose 124. This particular configuration of shieldnose 124 is disclosed in commonly assigned U.S. patent application Ser.No. 11/103,892, filed Apr. 12, 2005, the contents of which areincorporated in its entirety by reference herein.

With reference to FIGS. 11-14, in conjunction with FIG. 5, obturatormember 106 will be discussed. Obturator member 106 includes obturatorrod 158 and obturator penetrating head 160 at the distal end of theobturator rod 158. Obturator rod 158 defines proximal end 162 having ageneral semi-circular cross-section and being received withincorrespondingly dimensioned opening 164 of spring mount 142 of housingcover 110. The proximal end 162 further defines latch 166 which isreceived within side opening 168 of spring mount 142 in snap relationtherewith to secure the two components (see FIG. 5). In this regard,obturator member 106 is longitudinally fixed within obturator housing102. The sloped surface of latch 166 also provides for selectivedisengagement of obturator rod 158 from housing cover 110, e.g., by atool inserted within an opening of the housing cover 110, enablingobturator rod 158 to be interchangeable, e.g., with rods havingdifferent shaped tips.

Obturator penetrating head 160 includes central rod segment 170extending to arcuate leading surface 172 and substantially planardissecting segment 174 longitudinally spaced from the arcuate leadingsurface 172. Arcuate leading surface 172 is atraumatic to tissue and isspaced from dissecting segment a predetermined distance 174 “m”. Thisconsequent narrow profile provided by central rod segment 170 permitsinitial insertion within tissue and facilitates, e.g., dissection oradvancement within the tissue without an incising action. Planardissecting segment 174 includes opposed outer surfaces 176 having anarcuate character in cross-section, which extend or taper from centralrod segment 170 to an outer boundary of the planar segment 174. Outersurfaces 176 define a substantially asymmetrical or non-linear taperedarrangement, e.g., the contour of the opposed outer surface may define anon linear, complex shape. In one embodiment, outer surfaces 176 definea generally convex segment 178 adjacent central rod segment 170 leadingto a generally recessed or concave segment 180 outwardly of the centralrod segment 170. This arrangement provides a hollow ground appearance toouter surfaces 176 thereby assisting in advancement of penetrating head160 within tissue. Planar segment 174 functions as a dissecting elementto dissect tissue as arcuate leading surface 172 is advanced intotissue.

Penetrating head 160 further defines disc segment 182 which is spacedfrom arcuate leading end 172. Disc segment 182 is generally transverseto the longitudinal axis and maintains proper spacing of penetratinghead 160 within shield nose 124 to prevent lateral displacement of thepenetrating head 166. Disc segment 182 has longitudinal rails 184extending to the obturator rod 158. Rails 184 define a cross-sectionaldimension approximating the diameter of disc segment to also assist inpositioning penetrating head 160 within shield nose 124.

Referring to FIGS. 9, 10 and 15-17, penetrating head 160 is mountedwithin shield nose 124 with central rod segment 170 being receivedwithin and extending through central aperture 150 of the shield nose andplanar dissecting segment 174 received within slot 156 traversing theshield nose. In the extended position of obturator shield and shieldnose 124 depicted in FIGS. 9 and 10, at least arcuate leading surface172 and outer surface 176 of penetrating head 160 are exposed from theshield nose.

With reference now to FIG. 18, a method of use and operation of trocarassembly 10 will be discussed. Obturator assembly 100 is inserted withincannula assembly 1000 and advanced to where obturator housing 102 isapproximated with cannula housing 1002. Outer wall 118 of obturatorhousing 102 may be appropriately dimensioned to form a friction fit withannular element 1006 of cannula housing 1002 or may be coupled to eachother by conventional means including bayonet coupling, tongue-groove,etc. Obturator penetrating head 160 is applied against the tissue “T”such that arcuate leading surface 172 of central rod segment 170 engagestissue. Arcuate leading surface 172 may be manipulated to advance withina previously formed incision.

The surgeon thereafter begins to advance trocar assembly 10 through thebody wall of the patient. Shield nose 124 of obturator sleeve 104contacts the tissue “T” and is driven upwardly to cause the obturatorsleeve 104 to move proximally (depicted by directional arrow “v”)against the bias of coil spring 136 as shown in FIG. 19. Obturatorsleeve 104 continues its proximal retracting movement until shelf 144 ofshield collar 122 engages cross-beam 146 b of collar stop 146 as shownin FIG. 20. In this retracted position of obturator sleeve 104,obturator penetrating head 160 is exposed to dissect through the tissue.The surgeon may apply a distally-directed force to obturator assembly100 to cause penetration through the tissue in an atraumatic manner aspreviously discussed.

Once penetrating head 160 and shield nose 124 pass through the body wallof the patient, obturator sleeve 104 is driven distally under theinfluence of coil spring 136 to return to its original position of FIG.18. The obturator assembly 100 is removed from cannula assembly 1000 andsurgery is performed with instruments inserted through cannula assembly1000.

Except where noted otherwise, the materials utilized in the componentsof the presently disclosed trocar assembly generally include materialssuch as, for example, ABS, polycarbonate, stainless steel, titanium andany other suitable biocompatible metals and/or polymeric materials. Apreferred ABS material is CYCOLAC which is available from GeneralElectric. A preferred polycarbonate material is also available fromGeneral Electric under the trademark LEXAN. An alternative polycarbonatematerial which may be utilized is CALIBRE polycarbonate available fromDow Chemical Company. The polycarbonate materials may be partially glassfilled for added strength.

Although the illustrative embodiments of the present disclosure havebeen described herein with reference to the accompanying drawings, it isto be understood that the disclosure is not limited to those preciseembodiments, and that various other changes and modifications may beeffected therein by one skilled in the art without departing from thescope or spirit of the disclosure.

1. An obturator assembly, which comprises: an obturator housing; anobturator member mounted to the obturator housing, the obturator memberdefining a longitudinal axis and having proximal and distal ends, theobturator member including an interchangeable obturator rod and apenetrating end, the penetrating end defining a substantially planardissecting segment and a central rod segment extending from the planardissecting element; and an obturator sleeve coaxially mounted about theobturator member and adapted for reciprocal longitudinal movementbetween a retracted position and an extended position.
 2. The obturatorassembly according to claim 1 wherein the planar segment of thepenetrating end of the obturator member defines atraumatic outer edges.3. The obturator assembly according to claim 2 wherein the atraumaticouter edges of the planar segment are arcuate.
 4. The obturator assemblyaccording to claim 2 wherein the central rod segment a distal entrysurface, the distal entry surface being atraumatic.
 5. The obturatorassembly according to claim 4 wherein the distal entry surface of thepenetrating end is arcuate.
 6. The obturator assembly according to claim4 wherein the distal entry surface of the penetrating end is exposedfrom the obturator sleeve when in the extended position of the obturatorsleeve.
 7. The obturator assembly according to claim 2 wherein theobturator sleeve includes a generally tapered nose shield for at leastpartially accommodating the penetrating end.
 8. The obturator assemblyaccording to claim 2 wherein the atraumatic edges of the planar segmentof the penetrating end extends radially outwardly from the nose shieldwhen in the extended position of the obturator sleeve.
 9. The obturatorassembly accordingly to claim 2 wherein the obturator member ismonolithically formed.
 10. The obturator assembly according to claim 2wherein the obturator sleeve is normally biased toward the extendedposition thereof.